(1) Field of the Invention
Multi-element arrays are employed to improve signal-to-noise, and to obtain bearing and range of either near field or far field targets. The acoustic signals of the multi-element array are normally summed into a beamformer. A simple broadside beamformer may only sum the elements, while a more complex beamformer will consist of multibeam, steered and shaded networks. A good practice is to frequently run simulated targets through the beamformer to test the complex circuitry.
(2) Description of the Prior Art
The method normally employed requires lengthy memory or delay line storage to develop the synthesized wave fronts. The length of memory storage maximizes when simulating acoustic signals from an end fired array. Long arrays require large memories or long delay lines. The large memory approach can be easily addressed to present the wave fronts for both near and far field targets. However, the delay line approach is not as easily manipulated where it is necessary to change from the near field spherical wave front to the far field plane wave front.